The disclosure relates generally to high temperature semiconductor devices, and more specifically, to semiconductor devices for transient voltage suppression in high temperature environments.
Although silicon devices have been used for preventing sensitive electronics coupled in parallel to the TVS device from being subjected to voltage spikes caused by, for example, lightning strikes and being damaged, they are not suitable for high temperature operation. Silicon devices tend to leak higher current as temperature increases, with the current reaching unacceptably high values in ambient temperatures greater than approximately 150° C., which makes them unsuitable to be used in ambient temperatures of 225° C. or more needed for aviation applications requiring core engine-mounted electronics such as distributed engine control. Moreover, known TVS devices typically are packaged using epoxy encapsulation. Epoxy packaging tends to induce large thermal strains within the TVS device structure above approximately 185° C. and to begin to decompose.
Turbine engine instrumentation for both aviation and power generation applications often require expensive cooling, or moving the electronics further away from the sensors and actuators resulting in increased installation and wiring complexity and reduced sensor performance due to noise. The electronics used in distributed controls in the aircraft are subject to damage from voltage surges caused by lightning strikes and electromagnetic interference (EMI). At least some known applications use transient voltage suppression (TVS) devices, which may include features similar to a Zener diode. Commercially available TVS devices made of silicon are unable to be used to protect distributed electronics placed close to the engine core due to the high ambient temperatures they would be exposed to.